膝关节动态有限元模型的力学分析

Mechanical analysis of knee dynamic finite element model

背景:膝关节具有解剖结构复杂性,活动多样性的特点。目前人体膝关节的生物力学研究由于不能进行直接的人体实验而进展缓慢,在尸体上进行实验又不具备正常人体的生理环境,其实验结果并不准确。目的:采用了工程学的有限元分析方法,在无创、活体的条件下,研究膝关节各部位的受力情况。方法:利用CT图像建立膝关节的三维动态有限元模型,在膝关节0°-90°范围内分析前后交叉韧带和髌股关节的受力。结果与结论:前交叉韧带在屈膝0°时张力最大,然后逐渐减小,在屈膝50°-90°之间无明显变化,而后交叉韧带恰恰相反,在屈膝0°-50°时变化不大,之后逐渐增大,屈膝90°时达到最大值。髌股关节受力分析发现,髌股关节的压力是随着角度逐渐增大的。提示膝关节动态三维有限元模型能够逼真模拟膝关节活动,研究正常人膝关节各部位的受力,是骨科生物力学分析的有效工具。

BACKGROUND： Knee joint has the characteristics of complex anatomical structure and active diversity. The development of the biomechanical research of human knee joint is slow as in vivo experiments cannot be conducted. The experiments performed on corpse do not have the normal physiological environment of the human body, so the results are not accurate. OBJECTIVE： To investigate the force condition on different parts of the knee joint with engineering finite element analysis method in non-invasive and in vivo conditions. METHODS： CT image was used to build dynamic three-dimensional finite element model of the knee joint. The force on the anterior cruciate ligament, posterior cruciate ligament and patellofemorel joint was analyzed in the range of 0°-90° of knee joint.RESULTS AND CONCLUSION： According to our study we found that the anterior cruciate ligament had the largest tension when the knee joint flexed at 0°, then gradually decreased. There was no significant change when the knee joint flexed at 50° to 90°. The posterior cruciate ligament had the opposite changing trend： there was no significant change when the knee joint flexed between 0° to 50°, and then gradually increased, and the posterior cruciate ligament had the largest tension when the knee joint flexed at 90°. The analysis of the stress experienced on patellofemorel joint showed the stress on the patellofemorel joint was gradually increased along with the increasing of the angle. The dynamic three-dimensional finite element model of the knee joint was able to simulate the motion of knee joint. Studying the stress experienced on different parts of the human knee joint is an important tool for biomechanics analysis in orthopedics.